Liquid control system



April 16, 1940.

M. H. LOUGHRKDGE I LIQUID CONTROL SYSTEM Filed Dec. 10, 1936 $2 -12 2;f; 2 2}? 52-6 E- I Patented"Apr.l6,1940 g 7 2,196,999

UNITED STATES PATENT OFFICE LIQUID CONTROL SYSTEM Matthew H. Loughridge,Bogota, J. Application December 10, 1936, Serial No. 115,149 14 Claims.((1137- 8 This invention relates to a system for conthe delivery tankwhich controls the orificeof a trolling the flow of liquids by gravityand may be discharge pipe, as the buoyancy of the float is applied as asyphon. or as a float arrangement. reduced'this orifice is submerged topermit the This invention includes a bell and float arflow through thedischarge, and as the buoyancy s rangement for controlling the flow ofliquids from is increased the orifice israised. above the liquid ahigher to a lower level; another object of the to stop the discharge;The control is obtained invention is tocontrol the flow of liquids froma by fluid pressure which varies the buoyancy of higher to a lower levelby a device, responsive to the float. temperature change; another objectof the in: A receiving tank receives the discharge from 10 vention istocontrol the flow of liquids by a dethe delivery tank. Air is sealed andcompressed 1 vice responsive to atmospheric pressure; another in a bellin this tank as the liquid rises and a object of theinvention is tocontrol the flow of flexible tube connects this bell with the floatliquids by the specific gravity of the liquid itself whereby the airexpels part of the liquid from and another object of the invention is tocontrol the float and increases its buoyancy to stop the the flow ofliquids by the electrical conductivity flow. The buoyancy of the floatis independently 15 of the liquid itself. Other objects. of theinvencontrolled by a pressure fluid responsive to temtion will'be moreparticularly understood from perature; the buoyancy may also becontrolled the following specification and the accompanying by a valveresponsive to barometric pressure. drawing, in which: The buoyancy isfurther controlled by a magnet 29 Figil shows a belland floatarrangement with, which tends to raise the float'when energized. part ofthe apparatus sectioned. for the control The circuit of this magnet iscontrolled by a of theflowflof a liquid from-an upper to a pludeviceresponsive to the specific gravity of the rality of .lower tanks,-thisview also includes the liquid accumulating in the receiving tank, it maycontrol of the liquid by a device'responsive to also be controlled bythe electric conductivity of temperature and also by a device responsiveto the liquid. g5 atmospheric pressure, I In Fig. l the liquid from tankE flows into Fig.'.'2 is another arrangement of float control tanks Fand H and theflow is controlled by the fora liquid in. which the floatis controlled 'elec-' liquid level in both tanks F and H. Tank Etrically, controlled by the specific gravity of the connects by pipe I52with the control tank I5I in liquidand controlled by the electricalconducwhich the float I54 operates vertically on the 30 tivityof theliquid, and guide 202a. The float comprises a central cylin- Fig. 3' isa modification of the float and therdrical chamber'a, a second chamberbsurroundmostat control. ing {chamber a, and an outer chamber 0 sur-,The.present invention is in part, a continuarounding chamber 11.Chamber 0 connects by tion of the invention in co-pending applications,pipe IIJI with the bell I60 in tank F and it com 35 Serial No. 755,841,December 3, 1934, and now nects by pipe I02with the bell I60 in tank H.Patent No. 2,131,743, granted October 4, 1938, An overflow pipe I04connects tank F with tank and'Serial No. 47,045, October 28, 1935. Thein- H and the pipe I51 secured to the float I54, at vention is ofgeneral application forv controlling 206, base; nozzle I03 which ismoved up and the flow .of liquid by gravity and also by the 1 down withthe float I54 so that when it is in the 40 characteristic of the liquiditself, one use of the raised position th nozzle 13 i above t 1 1invention is in connection with seed germinating f the liquid in t 5 andthereby t machines as disclosed in U. S. Patent 2,051,994, chargethrough pipe I5'Iis stopped. On the other August 1936- P use for the YQP hand, .when the nozzle I03 is below the level of is in the mudhumldfymg the liquid in tank I5I', the liquid'flows through 4 machines,and other uses are in removing the discharge pipe lsTintotank F a when fg f f ggg system. for tank F is filled to the level of the dischargepipe trolling the flow of liquids from a higher to a 3 used fill lowerlevel which control may be obtained from It W be observed 'f the P andthe the quantity of liquid that has passed to the are connected 1nmultlple'through h lower level, from the characteristic of this liquid,plpe H h m T a apped in or. from atmospheric conditions or from aomeither 01 these bells 1S suflicient to raise the float bination ofthese conditions. through the chamber 0. It will be noted that the a Asshown, it is applied. ,by meansof afloat in seal of-theair in pipe IOIrequires liquid in both tanks F and H and the last tank to be filledraises the float and stops the flow.

While the chamber is suflicient to control the float I it is alsoindependently controlled by The float I54 is also controlled byatmospheric pressure through the chamber a. In this application a pipeHi, leading from chamber a is provided with a valve H5 which iscontrolled by lever H6 and the diaphragm III of the pressure responsivedevice I I8. Asarranged in the drawing, when the atmospheric pressureincreases it forcesthe diaphragm II'I inwardly into the vacuum chamberof H8 and thereby closes valve II5 and traps the air in chamber a,thereby increasing the buoyancy of the float. I54. On the other when thepressure on diaphragm II! is reduced the tension of the diaphragmthrough lever I I6, opens valve H5 and reduced the buoyancy of the floatI54. The device III! may be a hygrometer of the usual type arranged tocontrol valve H5.

, Each of chambers a. and b may be constructed of a capacity sufiicientto buoy the float, or they may be together constructedof sufficientcapacity to .buoy the float independently of the buoy:

ancy obtained from chamber 0,. When the'apparatus is used in ahumidifying system, the supply of .liquidto the tanks F or H iscontrolled both by temperature and by atmospheric pressure and theamount of liquid that may be supplied at a time is controlled by thebell and float arrangementdescribed. The humidifier is typicallyillustrated by the motor I95 having a fan at I06 deflecting an aircurrent through the slots I3'I over the top of tank H. The motor iscontrolled by the circuit III'I, switch I08, connected by rod N39, withthe float H0 in tank. H arranged so that the motor circuit isinterrupted when the tank is empty.

The construction in Fig. 2 is arranged to control the flow of the liquidby the specific gravity of the liquid and also by its electricalconductivity. The float I 54 is provided witha magnetic stem i23 movingwithin the solenoid magnet I22, connected by circuit I24 with thebattery I25 and with the photoelectric cell I26. The photo cell in thisarrangement, when it receives light from the light bulb I27, establishesthe circuit I24 and causes the solenoid I22 to lift the float I54 or, to

increase its buoyancy. The light from the bulb I2! follows the pathindicated by the dotted line through the aperture I28 inthe shield I29,moving in guide I30 and connected with the bulb I 3i, floating in theliquid in tank I36 and responsive to the specific gravity of the liquid;A predetermined specific gravity will float bulb I3I so that apertureI28 registers with the line of sight between I21 and I26, in any otherposition the light beam is interrupted and the magnet I22 is notenergized. In this application it will be noted that if, for instance, aheavier liquid is to be added to a lighter liquid in tank I36 until agiven specific gravity isreached, the control will stop the flow at thispoint by energizing magnet perature changes in. III without I22 andraising the float I54. This operation is, of course, reversible. l

The control of the liquid flow may also be regulated by the electricconductivity of the liquid through the electrodes I32 and I33 placed intank I36 which tank should be' made of insulatingmaterial. Theselectrodes, through'circuit I34 and resistance I35, complete the circuitI24 of mag: net I22 and thereby stopthe flow of the liquid.

In addition to regulatingthis,circuitv by the resistance I35, it isalsosubject. to the distance separating the electrodes-I32 and I33,'thearea of establishing a circuit that will energize magnet I22 and raisethe float.

The application in Fig. 2 shows the bellows I I3 used to raise and lowerthe position of orifice I03 relative to the float thereby changing theposition at which the float will discharge. bellows H3 connect byrod I38with lever I39 pivoted at I40 and connected at I4I with discharge tubeI5'I.. As the bellows contract due to a lowering of temperature theorifice N13 is raised in the guide I 42 secured to the float and wnenthebellows expand the orifice I03, is lowered relative to the float. Asshown in this drawing the BX: panding bellows increases the buoyancy of.the float causing it to rise as the orifice is lowered.

the bellows I I 3 is placed above the liquid -line and is secured to thefloat by bracket I43. The "piston these electrodes immersed in theliquid and to the The 30. If these two conditions were equal; they wouldv in cylinder I44 connects to the clamp-Hi5 of the orifice I03-so thatthe orifice is moveduppand down relative to the float I54 in response totemaffecting the buoyancy of the float itself. 1 I 1: v This inventionadmits ofa-va'riety of applications and may be installed complete,'-orin any of its combinations, or each ,system maybe used by itself tocontrol the flow of liquids according" to the conditionsunder which itis applied. The

apparatus is compartively inexpensive, has fewv moving partsand mostof'the flexible tubing can be made from rubber hose. H

In the operation of the system as illustrated in the diagrams, the floatmay be made of comparatively light material and be correspondinglysensitive to a change influid pressure in its chambers aiiecting itsbuoyancy. Thev flexible tube leading to the. discharge orifice may have.a specific gravity close to that of the liquid so that it offers littleresistance to the movement of the float when the liquid is either low orhigh in the delivery tank. The chambersa and c are open at the bottom,or communicate atthe bottom with the liquid in the tank so that fluidpressure applied at the top ofthese chambers dis places some of theliquid and increases the buoyancy. The chamber b also communicates withthe liquid in the tank at the bottom but the fluid pressure is confinedin the expansion chamber II3, which acts upon the air on top of theliquid, or on the liquid itself to displace the liquid from this chamberas the fluid pressure is increased.

The atmospheric control acts on the thermobulb III and upon thebarometer H8 and is 10- cated outside the liquid and, asshown,*operatesindependently of the liquid. 2 1

If the receiving tank F only is used and pipe I02 closed, their the airentrapped in bell I60 through pipe IOI is transferred to chamber of thefloat at the top, which displaces the liquid from this chamber andincreases the buoyancy of the float to stop the discharge. The height ofthe liquid in tank F at which this will occur is determined by the sizeand location of the bell in thetank which can easily be adjusted tooperate the float when the liquid reaches a predetermined height. If theliquid is slowly removed from tank F the pressure in bell I60 is therebylowered and also the pressure in chamber 0 of the float. This slightlylowers the float to permit a flow to the tank F to replace the liquidremoved'andthus the level of the liquid in tank F may be maintainedsubstantially constant.

If there is an increase in temperature that vaporizes the liquid in bulbII I, the chamber I I3, Fig. 1' is expanded and the buoyancy thus produced is added to the buoyancy obtained from bell 50- This would requirea lower level in tank F to release more of the holding pressure en'-trapped by the bell I60 before the replacement flow takes place. If thetemperature bulb is applied as in Fig. 3, its operation does not affectthe buoyancy of the float, but by lowering the nozzle I03 a greaterbuoyancy is required to out 01f the flow and hence the water level intank F must rise higher to produce the extra pressure necessary for theincreased buoyancy under these conditions. The temperature control maythus be applied to increase or decrease the normal level of the liquidin the receiving tank.

The barometer control as shown in Fig. 1 releases the air from chamber awhen the atmospheric pressure is reduced by opening valve II5.Atmospheric changes of'this kind usually take I place slowly so thatthis valve opens and closes slowly. When valve H is open the buoyancy ofchamber a is deducted from the buoyancy supplied by chambers c and b.This requires a higher level of the liquid in the receiving tank-tocompensate for they deduction of chamber w, or an increase of flow ofthe liquid as long'as valve I I5 is open. Under ordinary conditions theliquid flow from the delivery tank to the receiving'tank.

is comparatively rapid so that a state. of equalizatio'n is restored ina short time after valve II5 opens and the float is raised to shut offthe flow. If the liquid is used for humidifying purposes, it saturatesthe atmosphere and the barometer closes valve II5 with the air trappedin chamber a to restore the buoyancy as the float is lowered. If valveII5 should close when the float is in the lowered position there wouldbe little or no air entrapped in chamber a and this chamber would not beeifective in increasingthe buoyancy until an operation occurred in whichvalve II5 closed when the float was raised. It should be noted however,that if the liquid is drained from the delivery tank I5I and thenresupplied, the float becomes self restoring with the liquid pressureacting on chambers a, b and c from below.

In practice the bell control may be applied to prevent an overflow ofthe liquid in the receiving tank while the thermometer and barometercontrols may be used to vary the quantity of the flow at any one time.

In Fig. 1 the excess liquid flowing into tank F overflows into tank Hthrough overflow pipe I04 where it is distributed by a humidifyingsystem. The overflow limits the height of the liquid in tank F whichseals the bell I60 and the bell I60 in tank H becomes the controllingbell of the float. When the liquid rises to a predetermined height intank H the supply to tank F is cut oil, and the overflow ceases to tank1-1. This predetermined height is modified by the other controls whenthese are used. 5 It will be observedthat if the liquid is used fromtank'F more rapidly than from tank'H, the bell I60 remains sealed andthe lowering of pressure; in hell I60 will restore the flow from thedelivery tank until the predetermined liquid level 10 is restored. I

The application of the invention in Fig. 2 pro vides for the control ofthe liquid flow by the characteristic of the liquid in the receivingtank which control is applied electrically. The appli- 1 cation" isintended for control by a liquid that is heavy liquid is added to alightone, the specific gravity of the light liquid increases and incertain chemical applications it is desirable to arrest the flow when acertain specific gravity has been reached. Another application is wherean acid may be added to Water to obtain a certain degree of acidityafter which the flow should be stopped.

The height of the liquid in tank I36 may be regulated by the bell I60,or by other means, as byan overflow pipe I04 shown in Fig. l. Thespecific gravity is determined by the bulb I3I which is immersed in theinitial liquid. As the specific gravity changes by the flow from pipeI51 into tank I36,- controlled by the float, of a liquid having adifferent specific gravity from the initial liquid, the bulb I3l movesin response to 'the'change in specific gravity. The flow from pipe I51raises the liquid levelin tank I36 comparatively slowly which enablesthe liquids to mix and to slowly move the bulb'I3'I. When the bulb movesthe aperture I28 into the path of the light beam for the photo cell I26,magnet I22 raises the float and shuts off the flow. This condition 40remains effective to stop the flow when the rethe plates I32 and I33 aresubstantially immersed therein, the resistance of the Water will notmaterially affect the circuit of magnet I22 unless a high voltage isused in battery I25. Now if a comparatively small flow of acid issupplied to this tank from pipe I51, the water becomes a conductor inproportion to its acidity. The size and. position of the plates can beso adjusted together with the resistance I35 that a predeterminedacidity of the liquid will energize magnet I22 to raise the float andstop the flow. This condition will remain established until the acidityof the liquid is lowered, or until it is removed from the tank. MagnetI22 for operating the float is controlled by the specific gravity andalso by the acidity of the liquid. These controls are not independentlyoperative. at the. same time. The latter would require independentcircuits for each purpose.

It should be noted that since the float follows the liquid level of thedischarge tank the flow through the discharge pipe is constant for anyheight of the liquid in this tank.

Having thus described'my invention, I claim:

1. A liquid control system comprising a flrst tank containing the,liquid, a'second tank at a lower level for receiving the liquid, ahollowfloat in the first tank having an expansible chamber acting on theliquid in the tank, a discharge pipe having its intake controlled bysaid float, a bell in the second tank arranged to be sealed as theliquid rises in thetank and aconduit pneumatically connecting saidbellwith said expansi'ble chamber to increase the buoyancy of the floatas the liquid rises in the bell.

2. A liquid control system comprising afirst tankcontaining the liquid,a plurality of tanks at a lower level than the first tank, a dischargepipe for filling said tanks from the first tank, a float in. the firsttank controlling the intake of said discharge pipe and means in each :ofsaid plurality of tanks controlling said float to supply liquid to eachof said tanks.

.3. A liquid control system comprising a: first tank containing theliquid, a second tank for receiving the liquid, a discharge pipeconnecting said tanks, a float in the first tank controlling the intakeorifice of said pipe and means responsive to the specific gravity of theliquid in one of said tanks controlling'the buoyancy of said float.

4. A liquid control system comprising a first tank containing theliquid, a second tank for receiving the liquid, a discharge pipeconnecting said tanks, a float in thefirst tank controlling the intakeorifice of said pipe and means responsive to the electrical conductivityof the liquid in said receiving tank controlling the buoyancy of saidfloat.

5. A liquid control system comprising a first tank containing theliquid, a second tank for receiving the liquid, a discharge pipeconnecting said tanks, a float in the first tankhaving two independentexpansible chambers controlling the intake of said discharge pipe, achamber having an expansive medium therein connected with one of saidexpansible chambers and a second chamber having an expansive mediumtherein operatively associated with the other expansible chamber.

6. A liquid control, system comprising a first tank containing theliquid, a second tank'for receiving the liquid, adischarge pipeconnecting said tanks, a hollow float controlling the intake of saiddischarge pipe, pneumatic means responsive to the rise of the liquid inthe receiving tank, an .air pipe connecting said pneumatic means withsaid float to vary its buoyancy, and means responsive to temperaturechange varying the buoyancy of said float.

7. A liquid control system comprising afirst tank containing the liquid,a second tank for re-- ceiving the liquid, a discharge pipe connectingsaid tanks, a hollow float controlling the intake of said dischargepipe, pneumatic means ressponsive to the rise of the liquid in thereceiving tank, an air pipe connecting said pneumatic means with saidhollowfloatfor varying its buoyancy, a second means responsive tobarometric pressure and a third means responsive to temperature changevarying the buoyancy of said float.

8. A liquid control system comprising a first tank containing theliquid, a second tank forrreceiving the liquid, a discharge pipeconnecting said tanks, a float controlling the intake of said dischargepipe, a magnet controlling said float and means controlling the circuitof said magnet by the liquid in the receiving tank. 9. A liquid controlsystem comprising a first tank containing the liquid, a second-tank forre- I ceiving the liquid, at discharge pipe connecting said tanks, atfloat controlling the intake ofsaid discharge pipe a magnet controllingsaid float, a circuit including a photo-electric cell, controlling saidmagnet,. and means responsive to the a liquid in the receiving tankcontrolling said cir cuit. I

l0. A liquid control system comprisinga'first tank containing theliquid, asecond tank for receiving the liquid, a discharge pipeconnecting said tanks, a float controlling the intake of; said dischargepipe, a magnet controlling said float and means responsive to theconductivity of the liquid in said receiving tank controlling the circult of said magnet. I

11. A liquid cotrol system comprisinga first tank containing the liquid,a second tankforre: ceiving the liquid, a discharge pipe connecting saidtanks for the gravity flow of the liquid, a

fioathaving a plurality of expansible chambers I in the first tank,controlling the intake of said discharge pipe and independent means forsup:

to vary the buoyancy of said'float.

plying fluid pressure to each of said chambers 12. A liquid ,controlsystem comprising a first tank containing the liquid,'a plurality ofreceiving'tanks, a discharge pipe connectingsaid first flow of theliquid to said tanks progressively, a float controlling the intake ofsaid discharge pipe and having an expansible chamber acting on theliquid in the tank, a bell in each of said receiving tanks, pneumaticmeans connecting said bells 35 tank with said receiving tanks for thegravity with the expansible chamber of said float,so arranged that theair trapped by the rising liquid in the bell of the last tank filledoperates the float to stop the flow.

13. A liquid control system comprisinga first tank containing theliquid, a second tank receiv ing the liquid, a discharge pipe connectingsaid f tanks for the gravity flow of the liquid, afloat having aplurality of expanding chambersin-the first tank controlling the intakeof said discharge pipe, means responsive to the level of the liquid in,

the receiving tank pneumatically connected to I one of said chambers-andmeans responsive to atmospheric conditions connectedwith another of saidchambers for varying the buoyancy of said float. i 14 A liquid controlsystem comprising a first tank containing the liquid, a second tankreceivi ing the liquid, a discharge pipe connecting said tanks, a floatin the first tank controlling the intake of said discharge pipe, meansresponsive to the liquid in the receiving tank for varying the buoyancyof the float and means responsive to atmospheric conditionsindependently varying the buoyancy of the float.

MATTHEW H. LOUGHRIDGE,

